U. MINNESOTA (US)—The largest study of its kind definitively links the use of indoor tanning devices to increased risk of melanoma, the most serious form of skin cancer.

The study involving 2,268 Minnesotans found that people who use any type of tanning bed for any amount of time are 74 percent more likely to develop melanoma.

Frequent users are 2.5 to 3 times more likely to develop melanoma than those who never use tanning devices. (The study defines frequent uses as people who used indoor tanning for 50 plus hours, more than 100 sessions, or for 10-plus years. This increased risk applies similarly to all ages and genders.)

“We found that it didn’t matter the type of tanning device used; there was no safe tanning device,” says DeAnn Lazovich, lead researcher and associate professor of epidemiology at the University of Minnesota. “We also found—and this is new data—that the risk of getting melanoma is associated more with how much a person tans and not the age at which a person starts using tanning devices. Risk rises with frequency of use, regardless of age, gender, or device.”

Melanoma is one of the fastest increasing cancers across the United States and in Minnesota. About 69,000 people in the United States will be diagnosed with melanoma this year; nearly 1,000 of those people will be Minnesotans.

Although melanoma accounts for only about 4 percent of all skin cancer, it causes about 79 percent of all deaths from skin cancer. In a more advanced state, melanoma is especially difficult to successfully treat.

Before this study, indoor tanning has been only weakly associated with melanoma risk, Lazovich says.

“Most reports were not able to adjust for sun exposure, confirm a dose-response, or examine specific tanning devices,” she adds. “Our population-based, case-control study was conducted to address these limitations.”

Funding for this research was provided by the National Cancer Institute and the American Cancer Society.

Researchers from the VA Medical Center, Minneapolis; University of New Mexico Cancer Center, Albuquerque; and Brown University contributed to the work.